The first mistake people can make when cleaning their car is not to give the vehicle a pre-wash a good blast with a jet washer is perfect. This leaves the likelihood of paintwork damage high as so much grit and dirt are sat on the car before you clean it.
Pre-washing a car is to rid the car of dirt, insects, bird droppings and any other loose pollutant chemicals from the paint surfaces. Before you carry out a hand wash on the car. Soften the dirt and the surface of the paintwork and wheels.
Pre washing a car is a must to help keep the infliction of swirl marks, scratches and abrasions to an absolute minimum. The key is to remove as much dirt as you can before actually touching the car when using a jet washer do not forget to keep a healthy distance from the cars paintwork in some cases jet washing has been known to remove paint lacquer and if there are any imperfections like paint bubbles or rust a jet washer can remove the damaged paint work.
A pre-wash rinse can start the softening process. Using a pressure washer or hose work from the top down, rinsing the panels carefully. Pay particular attention to panel gaps and regions, which may trap dirt (inside roof rails for example) and rinse these out thoroughly.
A good pre wash product on the market is Snow foam this is used to cover the car in a film to loosen and softer dirt, insects,bugs and bird droppings just leave to work for 5-10 minutes then wash off with a pressure washer the results are fantastic and set you on the way for an effective easy wash.